7.3 Idles Rough, Runs Great Otherwise

[rempfer]

These things will run when you are way out of the ballpark timing-wise............

For example, I retimed my truck 2 weeks ago (60k miles on IP/injectors), to set it right, there was none of the standard "dime thickness" nonsense, I ended up advancing my pump over 1/4" in total!

I keep meaning to take a picture of the scratch marks I started at......... but it's dark right now, and I'm lazy

Not meaning to be a pest, but if you could bring yourself to do it I'd REALLY like to see those pictures before I start on my 1988 F-250 IDI....

 

[79jasper]

Why?
Yours likely won't be the same.

Sent from my SM-G892A using Tapatalk

 

[Why Me?]

Hey Guys,

New to the forum. I have searched and searched but was not able to find anything that is like this particular case.

My truck is a 1990 (N/A) 7.3. It has since had a hypermax T4 turbo setup at some point in time. Not too long ago I replaced the IP and injectors (maybe 300 miles). At idle I get a terrible vibration that almost feels like a miss and it seems to increase with RPM as well. There is no blue smoke at anytime at any temperature. All compression checked out within 10 psi of each other as well.. I can loosen the injector cap lines and all seem to effect idle similarly. It also passed the clear line test. Would engine mounts be next to question???

Pyro: Never above 1100 degrees. And runs excellent when not at idle.. or under load.

P.S. I replaced the IP with Delphi and injectors were from Pensacola.

Thanks!

its an IDI...they do run ruff at idle, and as soon as you leave the stop light it sounds fine...might be the new normal especially with clean exhaust indicates good timming

 

[Justin Short]

Finally figured it out! When I went to pull the injectors to send them back I pulled the very last one out and for some reason it hadn't sealed correctly. Cleaned both injector and bore and now runs smooth.

Thanks for the help!